


Discipline Alley

by SoloShikigami



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap (Undertale), BDSM, Don't get caught, M/M, Semi-Public Sex, Underswap Canine Squad, Underswap Muffet (Undertale), Underswap Papyrus (Undertale), Underswap Sans (Undertale)
Language: English
Status: Completed
Published: 2020-05-12
Updated: 2020-05-12
Packaged: 2021-03-02 20:07:48
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,039
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24152566
Author URL: https://archiveofourown.org/users/SoloShikigami/pseuds/SoloShikigami
Summary: Papyrus is late coming home, again, so Sans goes out to find him. Much to his dismay, he is at Muffet's. Again. Sans decides that it's time his little brother needs to be taught a lesson.
Relationships: Papyrus/Sans (Undertale)
Comments: 2
Kudos: 44





	Discipline Alley

**Author's Note:**

> Written for Megalotrash in November, 2018!

It should have been a fairly typical evening; Sans would come home from training, shower, and make dinner for him and his brother. Then they would watch NTT until they either got tired or frisky. Sans was prepared to be frisky this evening after the teasing his brother gave him that morning.

But there was only one problem when Sans came home - his brother was nowhere to be seen, and if he wasn’t at home, and Sans was pretty certain he wasn’t at his sentry station at this hour, then there was only one place that he could be.

* * *

  
Sans nearly threw open the door to Muffet’s Bakery Saloon, the smell of frosting , cake batter, and sugar assaulting his senses. It was crowded and loud, and there at the bar, surrounded by the Canine Squad and a few other Snowdin residents, was his brother. He was drinking a bottle of honey (Sans was never sure if Muffet just gave them to him or he swiped them - don’t other people have to use those? If so, hopefully Muffet washed them thoroughly when he finished), and cracking his horrible jokes.

“- and so I told him to go stuff an artichoke!” Papyrus said.

The monsters around them howled with laughter.

“What’s an artichoke?” Doggo asked.

But no one answered the question as they all noticed Sans marching towards his brother and the look on his face clearly said that he was not a happy monster. Papyrus was still laughing as he approached, either not noticing or not particularly caring.

“Papyrus!” Sans exclaimed, planting his feet firmly and crossing his arms over his chest as he glared at the tall, thin monster before him.

“Hm? Oh, hey there, bro,” Papyrus said, tilting the tip of the honey bottle at his temple in a casual sort of salute. “Didn’t see you come in.”

“Why are you not at home? You know these evenings you are due straight home after work!” Sans scolded.

“Come on, relax, have a scone, they’re pretty good,” Papyrus said, swiping one from the counter and holding it out to his brother.

Sans glared at the pastry as if it offended him before his big, bright blue eyes wandered slowly up to Papyrus’, his emotions as easy to read as large print.

The gathered crowd slowly began to back away; they didn’t know the true nature of the more-than-brotherly relationship between the two, but they knew that the smaller skeleton had high standards, an infinite well of magic, and while it didn’t take much to get him riled, like a true brother, Papyrus knew which buttons to push, and an angry Sans was not to be taken lightly.

“Papyrus,” Sans said, voice steady and firm. “You will accompany me home immediately.”

“Oh? Or what, bro?” Papyrus said, sitting up from his slouched position to lean forward in a challenging manner, tossing the scone to Lesser Dog, who happily caught it in his mouth with a pleased yip.

Sans also leaned forward slightly, sniffing a few times before he recoiled.

“Are you drunk?!” he asked indignantly.

The two skeletons had long since discovered that for some strange reason, honey had an odd effect on them; It wasn’t the strict definition of being drunk, as they seemed to have their mental capabilities for the most part, but there was a loss of coordination and their magic became sluggish and sloppy, very dangerous if they were trying to actually use it for destructive purposes.

“Nah, of course I’m not,” Papyrus replied, waving a hand dismissively, despite that the motion in and of itself made him waver on his stool.

“Unbelievable,” Sans huffed. “I’d rather continue our conversation at home, brother, so if you would please?”

“Or what?” Papyrus challenged again, setting the honey bottle down on the counter.

“I would rather continue this at home,” Sans said quietly.

“Uhm, Pap? You may want to just do what he says,” Muffet murmured behind him. “And I swear if you fight with him in my place again, your tab will be the least of your worries.”

“Oh, do not worry, Ms. Muffet,” Sans said loudly. “I am not in the custom of airing our laundry out in public!”

“But you hang our stuff outside all the ti-iiii—hey!”

As Papyrus was making his smart-ass retort, Sans walked over and bodily lifted the taller skeleton over his head.

“If you will excuse us!” Sans said brightly, grinning widely at everyone.

“Hey! Sans! Come on, put me down! This isn’t funny! You’re gonna hurt yourself! Or me!” Papyrus protested as Sans carried him outside. “Sans! Hey! Are you even listening to me?!”

Patrons held the door open for them as they exited, and the moment the doors shut again they all went back to minding their own businesses.

“You sure he’s gonna be all right?” Doggo asked.

“Yes, Sans will…” Dogaressa started.

“… take good care of him,” Dogamy finished.

While, again, no one knew for sure what went on in the skeleton household behind closed doors, the Dogi had noticed that Papyrus usually had his brother’s scent about him.

“Sans! Knock it off, already! What are you doing? Put me down!” Papyrus continued to exclaim as Sans started between Muffet’s place and the Librarby.

“If you don’t stop shouting, you’ll draw even more attention,” Sans warned him. “Unless, of course, that is what you want?”

While Papyrus tried to think of some other protest, he gasped as he was set none-too gently on top of a trash can.

“W-what are you doing?” Papyrus asked, watching Sans unbuckle his pants and reaching between his legs.

“You knew damn good and well what you were doing this morning,” Sans said, the hand in his pants moving in an unmistakable way, his other hand beginning to work on the front of Papyrus’ pants.

“S-sans! What are you doing?” Papyrus protested, pushing his hand away.

“You know exactly what this is all about.”

Sans let go of his cock so he could grab Papyrus’ hands roughly and drag him off the trash cans, forcing him to his knees. He moved behind him, slipping off his bandana to tie his hands behind his back quickly before gripping the hood of the orange sweatshirt and pulling him back against him. Papyrus gasped, but a pleasant shudder shook him as his brother ran his hands over his chest, the gloved fingers scratching across his ribs.

“This morning, you walked downstairs in a ratty, dirty, disgusting t-shirt that was obviously too small. You knew I had a full day and you knew that I was expecting you to be home to make good on the promises you whispered in my ear while I made breakfast,” Sans growled into his temple. “And I think I need to remind you what _this_ means.”

Sans had slipped a hand down the neck of the hoodie to grip onto the thick black collar that Papyrus kept hidden underneath it. Along one side was Sans’ name stitched in bright blue, so in case anyone did ever happen to see it, there would be no denying who Papyrus belonged to.

“Tell me, Papyrus, what does this collar mean?” Sans said in a gentle tone, his tongue darting out to draw a thin line towards the back of Papyrus’ jaw.

“It means I belong to you,” Papyrus answered, his voice shaking a little between being turned on and anticipation.

“What, exactly, belongs to me?” Sans asked, his mouth moving to hover over the few exposed neckbones above the collar.

“My body and my soul belong to you,” Papyrus whispered, his eyes squeezing shut as he tensed from the warm breath at his neck.

“Mmm, so, what gave you the idea that you were to go to Muffet’s instead of being home as I expected? Especially without you telling me? I worry about you, Papyrus, after all, you only have one HP; you need a magnificent monster such as myself to look after you.”

Papyrus nodded, unable to answer otherwise for a moment, his eyes opening a little to dart towards the entrance to the alleyway.

“I’m sorry, Sans, but please, could we go home?” Papyrus asked.

“Mmm, why? You seemed to want to test your independence, perhaps you want the town to know about our arrangement? In that case, feel free to make as much noise as you like.”

With that and a small, possessive growl, Sans bit down on Papyrus’ neck. A strangled cry just barely made it past his teeth, but Papyrus quickly clenched his mouth shut. His breathing sped up, only slowing when Sans released him and licked the mark to soothe it.

“Is this a new game you’d like to play, Papyrus?” Sans asked. “I certainly would like to see how much restraint you can have, if you’re up to it.”

Sans stood up straight, keeping Papyrus pulled back against him firmly, waiting patiently for him to calm and come to an answer.

“Continue,” Papyrus said, using their green light safeword, the tone slightly pleading as he looked up at his brother.

Sans smiled down at him and nodded.

“I’m glad to hear it.”

Sans moved to Papyrus’ front, pushed his pants down enough so they fell at his ankles, his cock bobbing invitingly in front of Papyrus’ face. Sans put a hand on top of the other’s head.

“I think you owe me a little something for worrying me, don’t you think, brother?” Sans asked.

Papyrus gave him a quick smirk before leaning forward and taking him into his mouth. Sans sighed, petting Papyrus’ skull as it bobbed, the orange tongue sliding along his shaft, his teeth gently nipping at the head now and then. A few times, Sans thrust forward, hoping to go just a little deeper into that wonderful mouth.

“Okay, Papy, that’s enough,” Sans murmured. But when Papyrus didn’t stop, Sans growled and gripped his head firmly. “I said enough!”

Papyrus pulled off, grinning impishly up at Sans who smirked back down at him.

“You’re going to regret that, younger brother,” Sans murmured. “I’m going to make walking home very difficult for you.”

Before Papyrus could begin to think of what Sans meant, he found himself picked up, his shorts shoved down roughly, and he was shocked to find that Sans was holding him poised above his cock. His back was to the wall to keep him steady, but Sans was holding his bodyweight all on his own.

“S-sans?!” Papyrus stammered.

“Remember, you don’t want to get caught,” Sans remarked with a grin before pulling Papyrus down, only needing a moment of maneuvering to bury himself deep in his entrance.

Papyrus’ head dropped back, a squeak barely escaping as he held tight to the idea that he really didn’t want anyone to come looking for them, and he barely had time to adjust before Sans was moving, impaling him over and over, hard and deep.

Neither of them lasted long, the thrill of the possibility of being caught, the quick foreplay, Sans riding high on the thought that he had the strength to do this all on his own and Papyrus also finding himself turned on by Sans’ pure power.

* * *

“Now, are you going to make sure you are home when I expect you to be? Or at the very least tell me if you aren’t going to be there?” Sans asked as he strode ahead of Papyrus.

“Yeah, bro, I hear you,” Papyrus said, limping a little with each step.

Sans stopped to look at Papyrus. “Are you sure you’re okay to get home?”

“Well, you don’t like using the shortcuts, and it’s not too far and- hey!” Papyrus yelped as Sans picked him up, one arm firm around his back and the other hooked under his knees. “Is this going to be a habit?!”

“It might! Mweh heh heh!” Sans giggled, grinning widely as he continued to march towards their house.

“Well, it is kind of a turn on,” Papyrus murmured low enough for only Sans to hear, a blush spreading across his face.

“I shall use it in more circumstances, then!” Sans said.

Papyrus smiled and leaned to kiss the side of Sans’ skull.

“Love ya, bro.”

“I love you, too, Papyrus.”

**Author's Note:**

> Like what you read? Please check out my social media for more fun!  
> [ My Tumblr](https://soloshikigami.tumblr.com/)  
> [ My Twitter](https://twitter.com/SoloShikigami)


End file.
